The 2 sencoin is a coin that was minted by the Empire of Japan at some point between 1912 and 1925 for use in the Ōshima Seishōen Sanatorium, a leprosarium located on the island of Ōshima in Takamatsu, Kagawa Prefecture. Like the 2 sen coin used outside the sanatorium, the coin used by the institution had a value equal to 0.02 yen prior to demonetization. A specialized 2 sen coin was used at Ōshima Seishōen instead of the normal 2 sen piece for fear that people could become infected with leprosy through contact with items lepers had touched. It has since been proven that leprosy cannot be transmitted through such means, so handling an example of the coin is not harmful to one's health.

The coin is composed of brass and is round in shape. Its value is inscribed vertically in Japanese as "貳銭" (romanized: Ni sen; English: "two sen"), with a considerable amount of space between both characters. The symbol "検" (ken), meaning "inspection" in English, is stamped twice to the left of the value, while the name of the reigning EmperorTaishō is written vertically in Japanese as "大正" to the right. A single "検" (ken) character is present on the reverse.